Attachment-plug.



No. 797,454. PATENTED AUG. 15,, 1905.- H, T PAISTE.

ATTAGHMENT PLUG APPLIOMION FILED JAN. 20, 1904.

UNITE STA.

HENRY T. PAISTE, OF Pl-IILADlELli'I-HA, PENNSYLVANIA.

@pecification of Letters Patent.

Patented Aug. 15, 1905.

Application filed January 20, 1904;. Serial No. 189,899.

To all w/wm 71/; may co/tcerrt:

Be it known that l, l'lIJNRY T. PAIs'rn, a citizen oi the United States, residing in Philadelphia, Pennsylvania, have invented certain Il m provements in Attachment-Plugs, of which the following is a specification.

My invention relates to certain improvements in that class of electrical apparatus designed to receive a pair of electric conductors and to be entered into a lamp or other socket.

The object of the invention is to provide a simple and inexpensive attachment-plug with its parts arranged so that they shall not easily become loosened nor have its operativeness interfered with even though exposed to continuous vibration. I

it is further desired to provide a plug with an improved means for holding certain of its parts permanently in position.

These objects I attain as hereinafter set forth, reference being had. to the accompanying drawings, in which--- Figure 1 is a sectional elevation of my improved attachment-plug, showing the relative positions of its various parts; and Fig. 2 is a sectional plan view on the line 2 2, Fig. 1, further illustrating my invention.

in attachment-plugs as at present made and used much trouble is frequently caused, particularly in that type of plug having a threaded shell as one of its terminals, by said shell becoming loose, and such annoyance is particularly liable to occur in situations where the socket is exposed to vibration, since it is under such conditions that the screws holding the parts of the device together will become loosened. Again, attachment-plugs as at present constructed are provided with a cap or covering-shell at one end, which is of a special form, thus'necessitating special dies and tools for its manufacture. By the improved construction adopted in my device, hereinafter described, it is possible to employ as a cap or covering-piece for the plug the well-known and universally-used cap ordinarily employed as part of the shell of a lamp-socket. By adapting the attachmentplug so that it is possible to use this wellknown form of cover I reduce very materially the cost of manufacture, since it is no longer necessary to provide special tools and dies to construct this portion 01'' the plug.

in the above drawings, A is a body portion, usually of porcelain or other suitable nonconductor of electricity, having a substan tially cylindrical portion a of a diameter less than that of the lamp-socket into which the plug is to lit and a portion a of a larger diameter adapted for the reception oi the cover-shell B. Said portion a is provided with a projecting llz'inge (0, against which fits the edge of the said cover-shell B, and this latter is provided with an opening in its top, in which is iixed an insulating-bushing I), it being noted that the said bushing isflanged in any desired manner, both internally and externally, so as to be permanently retained in position. The interior of the cover-shell is provided with a lining 7/. of insulating material, so that it will be seen that all portions both of the opening into the shell as well as the interior of the shell itself are insulated from conductors passing through said opening and into said interior. The portion a of the body of the plug has upon it a metallic shell (I, which in the form shown is threaded to engage a correspondingly threaded shell in a lamp or other socket. This shell is electrically and mechanically connected to a flat piece of metal 0 by means of an eyelet c, it being noted that the portion a oi? the body is provided with a longitudinal recess for the accommodation of said piece c. Opposite said recess and preferably extending parallel to it in the body It is a second longitudinal recess, and both of said recesses extend in the said part (1/ until they reach the part (1/. The front face of this latter portion of the body is recessed for the reception of the terminals (Z and (.Z', to which it is designed the conductors which enter through the opening in the bushing b shall be attached. One of these terminals (l is electrically connected to the piece (2 by means oi. a screw (1, while the other is engaged by the end of the screw (Z which extends completely through the portion (1/ of the body and holds in position a contact-plate d". For convenience a second. screw (1 is employed to hold the terminal plate (1: in position, and the head of this screw projects into one end of the recess opposite to that provided :for the piece 0. Said opposite recess is filled with a body of cementing material d, which may be fusible and which not only engages the head of the screw but enters the corrugation formed by the screw-threads of the shell C, so as to hold the latter immovably in place under operating conditions. it has frequently been found that the screw d as well as the screw (Z become loosened, this being to some extent d no to the slight movement of the shell 0 upon the pertion a of the body. By using cement in the manner shown movement of the shell is absolutely prevented, and in addition the head of the screw (Z is also embedded in the cement, so that it cannot move.

The cover-shell B is held to the body A by means of screws 5 usually two, which pass through reinforced portions of its lower edge and enter recesses in the porcelain or other non-conducting body of the shell. As shown, the lower edge of the cover-shell abuts upon the flange (4 so that there is no possibility of the rocking of said shell upon the body portion.

While in the drawings I have shown cement in but one of the two recesses of the part a, it will be understood that, if desired, it may be employed in the recess which contains the piece 0, although since I have found it amply suiiicient for all practical purposes to fill but one recess I have not further illustrated this special form of my invention.

I claim as my invention- 1. An attachment-plug having a body of non-conducting material, a metallic shell upon the same, said shell having an irregular surface, said body being provided with a recess extending adjacent to the shell, metallic terminals, means for electrically connecting said shell to one of the terminals, and a body of cement within said recess engaging the shell, substantially as described.

2. An attachment-plug having terminals for the attachment of electrical conductors, other terminals for engagement with a socket, one of said second terminals being in the form of a threaded shell, 21. body of non-conducting material supporting said terminals and provided with a recess adjacent to the threaded shell, with a body of material in said recess and engaging the shell, substantially as described.

3. An attachment-plug having a body of non-conducting material, terminals thereon,

of which one consists of a threaded shell, means for holding said shell in position on the body, with a mass of cementing material engaging the shell and the body, substantially as described.

4. An attachment-plug having a body portion of non-conducting material provided with a longitudinal recess, a threaded shell upon said portion, with a mass of material in said recess engaging the threads of the shell, and terminals for electrical conductors, substantially as described.

5. An attachment-plug having a body provided with a portion formed with a plurality of recesses, a threaded shell on said portion, a contact-piece and terminals for electrical conductors connected to the shell and to said contact-piece, means in one of the recesses of the body for forming electrical connection between the shell and one of the terminals, and fusible material in the other recess in engagement with the threads of the shell, substantially as described.

6. The combination of a body of non-conducting material, a metallic cover-shell for one end of same, said shell having an opening, an insulating-lining within the shell eXtend ing from the body of non-conducting material, an insulating-bushing in the opening of the shell having its end flanged to hold said lining, with terminals on the body for the attachment of conductors and other terminals for engagement with a socket, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HENRY T. PAISTE. Witnesses:

IVILLIAM E. BRADLEY, Jos. H. KLEIN. 

